/* Product introduction. Isolated from the application and authentication styles. */
:root { color-scheme: light; }
html { scroll-behavior: smooth; scroll-padding-top: 88px; }
.about-page { --ink:#1d1d1f; --muted:#62666c; --accent:#007b98; --line:#e7e8eb; margin:0; color:var(--ink); background:#fff; font-family:-apple-system,BlinkMacSystemFont,"SF Pro Display","PingFang SC","Microsoft YaHei",sans-serif; -webkit-font-smoothing:antialiased; line-height:1.6; }
.about-page *, .about-page *::before, .about-page *::after { box-sizing:border-box; }
.about-page h1,.about-page h2,.about-page h3,.about-page p { margin:0; }
.about-page a { color:inherit; text-decoration:none; }
.about-page button { font:inherit; cursor:pointer; }
.about-page [hidden] { display:none !important; }
.about-page a:focus-visible,.about-page button:focus-visible,.about-page summary:focus-visible { outline:3px solid #007b98; outline-offset:5px; }
.about-page ::selection { background:#c1eff5; color:#14323c; }
.about-page .wrap { width:min(1120px,calc(100% - 64px)); margin-inline:auto; }
.skip-content { position:fixed; top:-100px; left:16px; z-index:100; padding:12px 20px; background:#fff; border:1px solid var(--accent); border-radius:12px; }
.skip-content:focus { top:16px; }
.site-header { position:sticky; top:0; z-index:20; background:rgba(255,255,255,.9); backdrop-filter:blur(20px); -webkit-backdrop-filter:blur(20px); border-bottom:1px solid rgba(0,0,0,.07); }
.nav-shell { width:min(1120px,calc(100% - 64px)); min-height:72px; margin:auto; display:flex; align-items:center; justify-content:space-between; gap:28px; }
.brand { display:inline-flex; align-items:center; gap:9px; font-size:21px; font-weight:700; letter-spacing:-.6px; min-height:44px; flex-shrink:0; }
.brand svg,.brand-ai { color:var(--accent); }
.nav-links { display:flex; align-items:center; gap:30px; margin-left:auto; margin-right:10px; font-size:13px; }
.nav-links a { display:flex; align-items:center; min-height:44px; color:#4b4e54; transition:color .2s; }
.nav-links a:hover { color:var(--accent); }
.about-page .button { display:inline-flex; justify-content:center; align-items:center; gap:20px; min-height:52px; padding:12px 26px; background:var(--accent); color:white; border-radius:30px; font-size:16px; font-weight:500; white-space:nowrap; transition:background .2s,box-shadow .2s; }
.about-page .button:hover { background:#00667e; box-shadow:0 6px 20px #007b981c; }
.about-page .button-small { min-height:40px; padding:8px 18px; font-size:13px; gap:16px; }
.hero { text-align:center; padding-top:80px; }
.eyebrow { color:var(--accent); font-size:14px; font-weight:600; letter-spacing:1.2px; }
.hero .eyebrow { display:flex; align-items:center; justify-content:center; gap:8px; }
.status-dot { width:6px; height:6px; border-radius:50%; background:#0087a4; box-shadow:0 0 0 4px #0087a410; }
.hero h1 { margin-top:24px; font-size:clamp(48px,5.9vw,80px); line-height:1.2; letter-spacing:-3px; font-weight:650; }
.gradient-text { color:#007c96; background:linear-gradient(115deg,#007788 10%,#2377b8 68%,#5359a4); background-clip:text; -webkit-background-clip:text; -webkit-text-fill-color:transparent; }
.hero-description { margin-top:27px !important; color:var(--muted); font-size:19px; line-height:1.8; }
.hero-actions { display:flex; align-items:center; justify-content:center; gap:28px; margin-top:30px; }
.about-page .text-link { color:var(--accent); display:inline-flex; align-items:center; gap:12px; min-height:44px; font-size:16px; font-weight:500; }
.text-link:hover { text-decoration:underline; text-underline-offset:5px; }
.hero-footnote { font-size:12px; color:var(--muted); margin-top:20px !important; letter-spacing:1px; }
.product-stage { position:relative; margin:65px auto 0; scroll-margin-top:95px; text-align:left; max-width:1000px; }
.stage-glow { position:absolute; inset:-34px -25px 40px; background:radial-gradient(ellipse at 18% 45%,#bcecf180,transparent 52%),radial-gradient(ellipse at 88% 65%,#c5cff875,transparent 55%); filter:blur(30px); pointer-events:none; }
.demo-table-head,.demo-row { display:flex; align-items:center; justify-content:space-between; gap:15px; border-bottom:1px solid #edf0f2; }
.demo-caption { position:relative; margin:20px 0 0 !important; text-align:center; color:var(--muted); font-size:11px; }
.workflow { display:grid; grid-template-columns:repeat(3,1fr); gap:70px; padding:75px 40px 100px; }
.step-number { color:var(--accent); display:block; font-size:12px; font-variant-numeric:tabular-nums; margin-bottom:10px; }
.workflow h2 { font-size:22px; font-weight:600; letter-spacing:-.7px; }
.workflow p { color:var(--muted); font-size:14px; margin-top:12px; line-height:1.85; }
.section { padding-block:100px; }
.section-heading { margin-bottom:48px; }
.section-heading h2 { font-size:clamp(36px,4.2vw,54px); line-height:1.3; letter-spacing:-1.8px; font-weight:600; margin-top:18px; }
.muted { color:#74787e; }
.section-description { margin-top:24px !important; color:var(--muted); font-size:18px; max-width:620px; }
.feature-section { background:#f5f5f7; }
.feature-grid { display:grid; grid-template-columns:1fr 1fr; gap:24px; }
.feature-card { background:white; border-radius:26px; padding:42px; overflow:hidden; min-width:0; }
.feature-wide { grid-column:1/-1; display:grid; grid-template-columns:1fr 1fr; gap:40px; align-items:center; min-height:380px; }
.feature-kicker { font-size:13px; color:var(--muted); display:block; margin-bottom:18px; font-weight:500; }
.feature-card h3,.scenario-card h3 { font-size:34px; font-weight:600; line-height:1.35; letter-spacing:-1px; }
.feature-card p { font-size:16px; color:var(--muted); line-height:1.85; max-width:375px; margin-top:20px; }
.filter-visual { height:300px; position:relative; max-width:480px; width:100%; margin:auto; }
.filter-orbit { position:absolute; inset:16px 62px; border:1px solid #e4edf0; border-radius:50%; transform:rotate(-25deg); }
.filter-orbit::before { content:""; position:absolute; inset:30px -35px; border:1px solid #edf1f5; border-radius:50%; transform:rotate(55deg); }
.filter-core { position:absolute; width:94px; height:94px; top:50%; left:50%; transform:translate(-50%,-50%); border-radius:24px; background:linear-gradient(135deg,#f2fcfd,#f0f4fe); border:1px solid #fff; box-shadow:0 15px 40px #37738b18; display:grid; place-items:center; color:#15899e; }
.filter-core svg { width:43px; height:43px; }
.filter-tag { position:absolute; padding:13px 18px; display:flex; align-items:center; gap:17px; font-size:11px; color:var(--muted); border:1px solid #e9ecef; border-radius:13px; background:#ffffffed; box-shadow:0 8px 20px #273d5308; white-space:nowrap; }
.filter-tag strong { font-size:13px; color:var(--ink); font-weight:500; }
.tag-one { left:2%; top:18px; }.tag-two { right:0; top:77px; }.tag-three { left:0; bottom:57px; }.tag-four { right:7%; bottom:0; }
.difficulty-steps { margin-top:32px; padding:2px 0 0; }
.difficulty-steps>div { width:75%; padding:14px 16px; background:#f8fafb; border:1px solid #edf0f2; border-radius:12px; margin-bottom:10px; }
.difficulty-steps>div:nth-child(2) { margin-left:12%; }.difficulty-steps>div:nth-child(3) { margin-left:25%; }
.hint-demo { margin-top:39px; border:1px solid #e7e9ed; border-radius:15px; padding:20px; min-height:186px; background:#fbfcfd; }
.hint-demo>div:first-child { display:flex; align-items:center; justify-content:space-between; gap:12px; color:var(--muted); font-size:11px; }
.hint-demo button { padding:8px 0 8px 8px; border:0; background:transparent; font-size:12px; color:var(--accent); min-height:44px; }
.hint-demo p { margin-top:14px; font-size:13px; line-height:1.8; }
.hint-placeholder { margin-top:25px; display:grid; gap:10px; }
.hint-placeholder i { height:7px; border-radius:5px; background:#dce4e9; width:95%; }.hint-placeholder i:nth-child(2) { width:80%; }.hint-placeholder i:nth-child(3) { width:55%; }
.library-card { background:linear-gradient(120deg,#eef5f9,#f9fbfc); }
.list-stack { position:relative; padding:5px 22px 20px; }
.stack-sheet { position:relative; background:white; border:1px solid #e4eaef; padding:27px; border-radius:18px; box-shadow:0 16px 35px #20384f09; }
.back-sheet { position:absolute; inset:0 5px 25px 32px; transform:rotate(5deg); background:#f8fbff; }
.list-label { display:flex; justify-content:space-between; color:var(--accent); font-size:11px; }
.stack-sheet strong { display:block; margin:22px 0; font-size:22px; font-weight:500; line-height:1.5; letter-spacing:-.6px; }
.list-line { display:flex; justify-content:space-between; gap:12px; padding:12px 0; border-top:1px solid #edf0f2; font-size:12px; }.list-line span:last-child { color:var(--muted); font-size:10px; }
.source-note { color:var(--muted); text-align:center; font-size:12px; margin-top:30px !important; }
.difference-section { background:#16191d; color:#f5f5f7; }
.difference-section .eyebrow { color:#79d5e6; }.difference-section .muted { color:#a4aab2; }.difference-section .section-description { color:#b5bac2; }
.comparison { border-top:1px solid #3a3f45; }
.comparison-header,.comparison-row { display:grid; grid-template-columns:1fr 1.4fr 1.4fr; gap:36px; }
.comparison-header { padding:24px 0; border-bottom:1px solid #3a3f45; color:#b5bac2; font-size:13px; }.comparison-header span:last-child { color:#7ed3e4; font-weight:600; }
.comparison-row { padding:28px 0; border-bottom:1px solid #30353b; align-items:start; }.comparison-row h3 { font-size:17px; font-weight:500; }.comparison-row p { font-size:15px; color:#b5bac2; line-height:1.85; }.comparison-row p:last-child { color:#f1f4f6; }
.comparison-note { margin-top:24px !important; color:#a4aab2; font-size:12px; line-height:1.9; max-width:950px; }
.scenario-grid { display:grid; grid-template-columns:1fr 1fr; gap:24px; }
.scenario-card { padding:44px; border-radius:26px; display:flex; flex-direction:column; }.topic-card { background:#edf5f8; }.stage-card { background:#f3f1f8; }
.scenario-card>p { color:var(--muted); margin-top:24px; font-size:16px; line-height:1.9; }
.scenario-prompt { padding-top:26px; margin:30px 0 22px; border-top:1px solid #182c3b18; }
.scenario-prompt>span { color:var(--muted); font-size:11px; }.scenario-prompt p { font-size:15px; line-height:1.9; margin-top:11px; }
.scenario-card .text-link { margin-top:auto; }
.faq-section { display:grid; grid-template-columns:1fr 1.5fr; gap:80px; padding-block:12px 105px; }
.faq-section h2 { font-size:32px; line-height:1.5; letter-spacing:-.8px; font-weight:600; margin-top:18px; }
.faq-list details { border-bottom:1px solid var(--line); }.faq-list details:first-child { border-top:1px solid var(--line); }
.faq-list summary { list-style:none; display:flex; align-items:center; justify-content:space-between; gap:20px; padding:24px 0; cursor:pointer; font-size:15px; font-weight:500; }.faq-list summary::-webkit-details-marker { display:none; }.faq-list summary span { color:var(--muted); font-size:20px; transition:transform .2s; }.faq-list details[open] summary span { transform:rotate(45deg); }
.faq-list p { color:var(--muted); font-size:14px; line-height:1.9; padding-bottom:25px; }
.closing { text-align:center; background:radial-gradient(ellipse at 50% 100%,#e3f2f780,transparent 70%),#f7f8fa; }.closing-logo { color:var(--accent); margin-bottom:28px; }.closing h2 { font-size:clamp(34px,4.5vw,58px); font-weight:600; line-height:1.35; letter-spacing:-1.5px; }.closing p { margin-top:24px; color:var(--muted); font-size:17px; }.closing .button { margin-top:30px; }
.site-footer { padding-block:30px; display:flex; justify-content:space-between; gap:20px; color:var(--muted); font-size:11px; }.site-footer>div { display:flex; gap:24px; }.site-footer a { display:inline-flex; align-items:center; min-height:44px; }.site-footer>span { align-self:center; }.site-footer a:hover { color:var(--accent); }
/* Visibility is never gated by JS; animation only enhances already visible content. */
@keyframes section-arrive { from { opacity:.4; transform:translateY(20px); } to { opacity:1; transform:translateY(0); } }
.reveal.is-arriving { animation:section-arrive .55s ease-out both; }
@media (max-width:1000px) { .demo-sidebar { padding-inline:10px; }.product-body { grid-template-columns:165px minmax(0,1fr); }.demo-content { padding:24px; }.workflow { gap:30px; padding-inline:15px; }.feature-card,.scenario-card { padding:32px; }.feature-wide { gap:20px; }.faq-section { gap:45px; }.filter-tag { padding:11px; gap:10px; }.nav-links { gap:20px; }.feature-card h3,.scenario-card h3 { font-size:30px; } }
@media (max-width:767px) {
  html { scroll-padding-top:80px; }
  .about-page .wrap,.nav-shell { width:calc(100% - 40px); }.nav-shell { min-height:64px; }.nav-links { display:none; }.about-page .button-small { min-height:44px; }
  .hero { padding-top:56px; }.hero h1 { font-size:clamp(40px,8vw,58px); letter-spacing:-1.5px; margin-top:23px; }.eyebrow { font-size:12px; }.hero-description { font-size:16px; margin-top:24px !important; }.hero-actions { gap:15px; flex-wrap:wrap; margin-top:25px; }.hero-actions .button { font-size:14px; padding-inline:23px; }.hero-actions .text-link { font-size:14px; }.hero-footnote { font-size:10px; margin-top:15px !important; }
  .product-stage { margin-top:45px; }.stage-glow { inset:-10px 0 30px; }.window-bar { padding-inline:14px; font-size:10px; }.window-dots { gap:4px; }.window-dots i { width:6px; height:6px; }.demo-label { font-size:9px; }.product-body { grid-template-columns:1fr; }.demo-sidebar { display:none; }.demo-content { padding:19px; }.demo-controls { margin-bottom:23px; }.demo-controls button { min-height:44px; }.demo-question { font-size:12px; gap:10px; margin-bottom:22px; }.demo-question p { min-height:66px; }.demo-answer { padding-left:0; }.ai-spark { margin-left:0; }.answer-title h2 { font-size:17px; }.demo-answer>p { font-size:11px; min-height:40px; }.demo-row { min-height:58px; font-size:11px; gap:8px; }.demo-row>span:first-child { gap:8px; }.demo-row b { display:none; }.demo-row .diff-badge { font-size:9px; padding:3px 5px; }.demo-followup { font-size:10px; padding:12px 10px; min-height:57px; }.demo-caption { font-size:10px; padding-inline:10px; }
  .workflow { grid-template-columns:1fr; gap:30px; padding:48px 12px 60px; }.workflow article { position:relative; padding-left:43px; }.step-number { position:absolute; left:0; top:4px; }.workflow h2 { font-size:21px; }.workflow p { margin-top:7px; font-size:14px; }.workflow br { display:none; }
  .section { padding-block:64px; }.section-heading { margin-bottom:30px; }.section-heading h2 { font-size:35px; letter-spacing:-1.3px; margin-top:16px; }.section-description { font-size:16px; }.feature-grid,.scenario-grid { grid-template-columns:1fr; gap:18px; }.feature-wide { grid-column:auto; grid-template-columns:1fr; gap:20px; }.feature-card,.scenario-card { padding:30px 26px; border-radius:22px; }.feature-card h3,.scenario-card h3 { font-size:29px; }.feature-card p { font-size:15px; margin-top:16px; }.feature-kicker { margin-bottom:15px; }.filter-visual { height:280px; max-width:400px; }.filter-tag { gap:10px; padding:10px 12px; font-size:10px; }.filter-tag strong { font-size:11px; }.filter-core { width:75px; height:75px; border-radius:19px; }.filter-core svg { width:34px; height:34px; }.tag-one { left:0; top:16px; }.tag-two { top:76px; }.tag-three { bottom:60px; }.tag-four { right:0; }.filter-orbit { inset:20px 40px; }.filter-tag .diff-badge { font-size:10px; }.difficulty-steps { margin-top:27px; }.hint-demo { margin-top:28px; }.list-stack { margin-top:10px; padding-inline:3px; }.stack-sheet { padding:23px; }.back-sheet { inset:0 -3px 25px 16px; }.source-note { text-align:left; font-size:11px; }
  .comparison-header { display:none; }.comparison-row { display:grid; grid-template-columns:1fr; gap:17px; padding:25px 0; }.comparison-row h3 { font-size:18px; }.comparison-row p { font-size:14px; }.comparison-row p::before { content:attr(data-label); display:block; font-size:11px; color:#a4aab2; margin-bottom:4px; }.comparison-row p:last-child::before { color:#7ed3e4; }.comparison-note { font-size:11px; }
  .scenario-card>p { font-size:15px; }.scenario-prompt { margin-top:25px; }.scenario-prompt p { font-size:14px; }.faq-section { grid-template-columns:1fr; gap:30px; padding-block:0 64px; }.faq-section h2 { font-size:30px; }.faq-list summary { font-size:14px; }.faq-list p { font-size:14px; }.closing h2 { font-size:34px; letter-spacing:-1px; }.closing p { font-size:15px; }.site-footer { flex-direction:column; gap:8px; padding-block:22px; }.site-footer>span { align-self:flex-start; }.site-footer>div { justify-content:space-between; gap:10px; font-size:10px; }
}
@media (prefers-reduced-motion:reduce) { html { scroll-behavior:auto; }.about-page *,.about-page *::before,.about-page *::after { animation:none !important; transition:none !important; } }
@media (forced-colors:active) { .gradient-text { background:none; -webkit-text-fill-color:currentColor; }.button,.demo-controls button,.feature-card { border:1px solid ButtonText; } }

.workspace-screenshot{position:relative;display:block;overflow:hidden;border:1px solid #dfe3e7;border-radius:18px;background:#f8fafc;box-shadow:0 26px 64px -36px #33445c55;}
.workspace-screenshot img{display:block;width:100%;height:auto;}
.workspace-preview figcaption{position:relative;text-align:center;margin-top:18px;font-size:12px;color:var(--muted);}
.workspace-preview figcaption a{display:inline-flex;align-items:center;min-height:44px;color:var(--accent);margin-left:12px;}
@media(max-width:760px){.workspace-screenshot{border-radius:12px;}.workspace-preview figcaption{line-height:1.8;}.workspace-preview figcaption a{display:flex;justify-content:center;margin-left:0;}}